The present invention relates to a vacuum cleaner tube shaft having an upper end and a lower end, the upper end being connected to a tube handle or the like communicating with a vacuum source and a particle separating means and the lower end being connected to a nozzle, the tube shaft comprising at least two sections arranged telescopically with respect to one another.
Tube shafts of the type mentioned above are previously known and are used to adjust the length of the tube shaft with respect to the height of the operator in order to achieve a comfortable working position. A further advantage is that such a tube shaft is rather space saving when it is pushed together for storage. Previously known tube shafts comprise straight, stiff tube sections which means that such tube shafts are easy to handle on open floor surfaces but create problems when cleaning beneath low furniture and objects. In order to reach below these objects the operator has to bend over and lower the tube shaft such that the nozzle reaches sufficiently far under the object. This creates an uncomfortable working position and makes cleaning work cumbersome, particularly for elderly people.
In order to eliminate this problem it has previously been suggested, see WO 89/07412, to use a flexible element such as a hose between two sections of the tube shaft making it possible to place the lower section of the tube shaft in such a position that it is parallel to the floor surface. However, this arrangement is very primitive and makes it difficult to guide the tube shaft in its normal working position because of the flexibility of the hose. A similar arrangement, but with complementary elements to stabilize the two sections with respect to one another, is also previously known, see SE 9600650. Unfortunately, this arrangement is very complicated because of the existence of several ball joints, telescopically arranged components and complementary tube sections.
Further it is previously known, see JP 7255653, to manufacture the complete tube shaft or parts of it from flexible material which means that the tube shaft can be pushed in below objects and become bent when contacting the objects. Even if such a tube shaft is pleasant, in the abstract, it is difficult to find material compositions giving the necessary flexibility while, at the same time, providing sufficient rigidity or stability during normal use.
Moreover, U.S. Pat. No. 1,012,195 and U.S. Pat. No. 1,104,148 describe other types of arrangements for facilitating cleaning operations below furniture. U.S. Pat. No. 1,012,195 describes a tube shaft comprising two parts. The two parts include a lower straight part and an upper handle part. The upper handle part has a short air inlet section that is inclined with respect to an elongated air outlet section. When cleaning below furniture, the upper part must be turned or rotated about 180.degree.. This, however, means that the handle part has to be moved to a position near the floor which is just as uncomfortable as the position required when using ordinary tube shafts.
U.S. Pat. No. 1,104,148 describes an arrangement having a bent tube shaft that can be turned through 90.degree. at each side of a central upraised position. However, when the tube shaft is turned to one of the side positions the operator is forced to move the handle part towards the floor in order to reach under furniture. Consequently, this arrangement has the same disadvantages as the arrangement described-above with regard to U.S. Pat. No. 1,012,195.